A combined bio-system to improve effluent water quality from sewage wastewater plants for agricultural reuse

A continuous lab-scale integrated bio-system was conducted to treat sewage wastewater from Abu-Rawash wastewater treatment plant (WWTP). The bio-system showed high efficiency in removing chemical oxygen demand (COD), biological oxygen demand (BOD 5 ), and total suspended solids (TSS). The experimental analysis results indicated that the maximum COD removal and methane yields were 97.6 and 13.74 mmol CH 4 /Kg COD at a hydraulic retention time (HRT) of 6 h, respectively. Zn, Mn, and Fe were removed at a high rate of up to 96.6%. The sponge bio-carriers have improved overall treatment performance and substantially improved mixed liquor volatile suspended solids/mixed liquor suspended solids (MLVSS/MLSS) ratio at an appreciated range, and the total pathogenic organisms were removed up to 99.8% in the second stage. Because the innovative bio-system enables a rapid startup process, is simple to use, and is inexpensive, it can provide an economically feasible alternative for wastewater management and could be extended to full-scale applications for agricultural purposes.